This invention relates to methods and apparatus for the assembly of dynamoelectric machines such as small (or fractional horsepower) motors.
In the past it has been the general practice in assembling a rotor within a stator of a small motor to place the rotor assembly in the stator bore and to space the rotor from the surface of the stator bore using shims or the like between the two elements. A permanent assembly is formed with end bells that secure the rotor within bearings and are secured themselves to the stator core after which the shims must be removed from the air gap. The practice of this technique, although generally successful, involves considerable labor and expense and is subject to manual skill to provide consistently successfully assembled motors with an air gap that permits operation without danger of contact between the rotor surface and the inside of the stator.
Other motor assembly techniques have been used and proposed particularly in relation to large dynamoelectric machines. Examples of such techniques are contained in U.S. Pat. Nos. 3,375,382 and 3,716,912. There remains interest in providing a simple procedure and mechanism for the assembly of small motors without the use of shims or other intermediate support elements between the rotor and stator.